ABB PFEA111-20 3BSE028140R0020 Electronic Tension Controller

What is a microcontroller?

You might not know it, but you probably have many of these in your home! A microcontroller is an integrated circuit (IC) or “chip” commonly used in devices with electronic circuitry in the home. You may have heard of microprocessors , such as the Intel Pentium , which are used as the CPU (Central Processing Unit) in a computer, essentially its “brain.” A microprocessor is an integrated circuit used to process instructions in a computer program, perform calculations, and send and receive data from memory and disk. A microcontroller is a specific type of microprocessor. It differs from a regular microprocessor in the following ways:

It has built-in I/O (input/output) functionality. Therefore, it can read and write digital and analog values/status and connect directly to the “real world.” Unlike microprocessors, microcontrollers can be directly connected to switches, buttons, LCD displays, LEDs, relays, and serial ports.

Microcontrollers are typically used for specific tasks in devices of medium to low complexity. This contrasts sharply with the powerful digital processing microprocessors used in PCs that handle a wide variety of software applications.

Microcontrollers are commonly used in battery-powered portable devices, such as digital cameras. Therefore, they typically consume little power and current (unlike the cooling fans that cool microprocessors in desktop computers).

Compared to the microprocessor in a PC, the RAM in a microcontroller typically ranges from 64k to as little as 1k.

The program in a microcontroller is typically stored in EPROM or EEPROM. This is a non-volatile memory (the program is not lost when the device is turned off) that can be continuously erased and rewritten.

microcontrollersApplications of

Many devices use microcontrollers. Some examples:

The burglar alarm contains a microcontroller chip that connects to the keyboard, display, and sensor /contact inputs. The microcontroller is typically a self-contained chip, with the ALU (Arithmetic Logic Unit), memory, and I/O all contained within a single integrated circuit.

Earlier automatic washing machines used a cam switch to sequence operations within a wash cycle. This was a rather complex switch, mounted at the end of the knob shaft you used to select the washing program. Newer machines use a microcontroller to sequence operations. Other appliances such as microwave ovens and dishwashers may also contain microcontrollers.

The television uses a microcontroller to handle channel selection and read the state of the buttons on the television.

The microcontroller is used for engine control and displaying information on the vehicle’s dashboard.

Digital cameras use microcontrollers to handle input from buttons, image capture, and display control.

Microcontroller Examples

Some commonly used microcontrollers:

Zilog Z8

Intel 8051

Texas Instruments TI MSP430

Atmel AVR